(b) Intermediate sensitivity position - less
(a) Install the header (subpara b).
than 5 MVAC RMS.
(b) Install the terminal board (subpara c).
(c) Low sensitivity position - less than 1.5
(c) Install the capacitor (subpara d).
f. Testing for Correct Phasing of Module.
(2) Place test pin (FSN 6665-893-0023) in re-
(1) Place search head on mine detector phasing ceiver coil recess on right side of search head. Measure
voltage at terminal 4. Repeat measurement with test
(2) Balance mine detector to less than 5 MVAC pin on left side of search head. The following output
RMS in the intermediate sensitivity position. Output voltages should be obtained:
voltage is measured on A5 board (FO-1) between termi-
(a) High sensitivity - 325 MVAC RMS plus or
nal 4 and ground.
minus 120 MVAC RMS above any balance level less
(3) Place magnetite tube in slots on right side of than 15 MVAC RMS.
phasing fixture and measure voltage at terminal 4.
(b) Intermediate sensitivity - 75 MVAC RMS
(4) Repeat measurement with magnetite on left plus or minus 28 MVAC RMS above any balance of less
side of phasing fixture.
than 5 MVAC RMS.
(5) Voltage measurements should be less than 400
(c) Low sensitivity - 19 MVAC RMS or minus 7
MVAC and within + or - 5 percent of each other.
MVAC RMS above any balance level of less than 1.5
(6) Adjust screw in variometer to obtain correct MVAC RMS.
phasing if necessary.
g. Testing for Detector sensitivity.
(1) Balance the mine detector with search head at
least 3 feet from metallic objects using the "R" and "X" headset assembly.
controls. The output voltages measured at terminal 4
b. Cleaning. Wipe the headset with a clean, dry
on A5 board are as follows.
(a) High sensitivity position - less than 15
c. Inspection. Inspect headset assembly for breaks,
cracks, deteriorated cushions, broken, cut, or corroded
electrical leads and terminals.